Headline, March 09 2022/ ''' '' MASTER ENGINEERING MASCOT '' '''

''' '' MASTER ENGINEERING 

MASCOT '' '''

ANCIENT BUILDING MATERIALS. Roman civil engineering has many lessons for the modern world.

THE ROMAN WERE MASTER BUILDERS. Many of their works, from the Pantheon and the Colosseum in Rome itself, to the Pont du Gard in southern Gaul and the equally impressive aqueduct of Segovia, in Spain, have withstood ages.

What damage has been done to such constructions is more often the result of stone robbery than structural failure.

Roman work of another sort has survived for centuries, too. ''De Architectura'' is a ten-book series by Marcus Vitruvius Pollio, an engineer and architect of the first century BC, who is believed by many scholars to have worked with Julius Caesar on some of his military campaigns.

These volumes include various tips intended to ensure that buildings ''don't fall into ruins over a long passage of time ''.

One reason for Roman engineers' success was concrete. [The Pantheon's roof is the largest unsupported concrete dome in the world.] Roam concrete is known to defy the centuries without losing much of its firmness. Indeed, it can even get stronger with age. How this happens is only now coming to light.

Part of the explanation lies in the volcanic rocks of areas such as the Alban Hills, south-east of Rome, and Pozzuoli, near Naples. These provided crucial ingredients.

As Vitruvius himself describes, the cement Romans used to bind the aggregates of concrete was a mixture of lime and volcanic ash. [The aggregates themselves were generally sand or crushed volcanic rock - which, in case of the Pantheon, included pumice, to make the structure lighter.]

Several recent studies have shown that the ash not only contributed to the concrete's strength and durability, but also enhanced cohesion between the aggregate particles after the mixture had been cured.

This happened when water seeped in, dissolving some of the volcanic minerals and creating calcium  aluminosilicate hydrates [C-A.S.H], the main binding material in the concrete. That also slowed the propagation of microscopic cracks. Moreover, some crack walls showed C-A-S-H infill - an indication that Roman concrete possessed a certain self-healing power.

In one of these studies, published in 2021, a team led by Marie Jackson of the University of Utah and Admire Masic of the Massachusetts Institute of Technology described the structure of the mortar [ a fine form of concrete ] of a brick wall in the tomb of Caecilia Metella, which stands beside the stretch of the Appian Way between Roma and the Alban Hills.

In part, of its solid masonry [so solid that it was repurposed as the keep of a castle during the Middle Ages], this building is one of the best-preserved monuments decorating the antique Roman highway.

The researchers studied how leucite, a potassium-rich volcanic mineral, dissolved in the water and reconfigured the chemical bonds between the cement and the aggregates, strengthening the interfaces between them, and making the whole structure more resilient.

This volcanic touch is, though, only part of the story. Lime, the other ingredient of Roman cement, also had a role in the post-curing strengthening of concrete.That, at least, is the conclusion of another paper by Dr. Masic, and a group of colleagues, which has just been published in Science Advances. 

''Roman concrete'', says Didier Snoeck, a structural-design engineer at the Free University of Brussels, in Belgium, ''shows that modern cement, of which the production emits huge amounts of CO2, is not indispensable for strong and durable concrete.''

''We can't,'' he says, ''replace all Portland cement with volcanic material, due to the necessary volumes of concrete to build infrastructure, but we can do it partially. And we can also use fly ashes, blast furnace slags and limestone calcined clays instead.''

Studying Roman concrete could also help modern engineers develop recipes for more durable, self-healing concrete. Increasing concrete's lifespan would mean less repair and renovation was needed, helping buildings last longer.

Who knows? Some of them might even outlast the Pantheon and the Colosseum.

The Honour and Serving of the Latest Global Operational Research on Science & Technology, continues. The World Students Society thanks The Economist.

With respectful dedication to Romans, the field of Engineering, and then Students, Professors and Teachers of the world.

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